Car Audio

Among the most under-appreciated components in any audio system are the speakers. You could be using the best source unit on the planet, an amazing amplifier, and the most esoteric of interconnects and speaker cables – but if you don’t have great speakers, you still won’t have great sound. Your speakers are the only link between your electronics and your ears, so choosing great speakers is critically important to reproducing great sound. This article discusses what you get when you spend more money on speakers.

More Power Handling

Several factors limit the ability of a speaker to convert an electrical signal into speaker cone motion. One such limit is thermal capacity – just how much heat the voice coil, tinsel leads, former and cone can handle before one of them fails. Heat is the number-one enemy of speakers. Most of the power you send to your speakers is converted to heat rather than to sound – in fact, probably 95% or more is converted to heat.

As the quality of speakers increases, you often encounter a larger voice coil and better cooling technologies. These features, coupled with tighter tolerances around the voice coil, result in a speaker that can absorb more energy without failing.

More Excursion

Often tied directly to how much power a speaker can handle is the distance the speaker cone can move forward or back. This specification is called excursion. For most speakers, the specification for excursion is called Xmax. Xmax is the distance the cone can move in one direction without the voice coil moving out of the magnetic field, and the measurement is typically provided in millimeters.

A second and often equally important specification is Xmech or Xsus. These specifications describe the physical limit of how far the cone can move, based on the design of the suspension (spider and surround). A speaker can be pushed past the Xmax limit, but as this happens, distortion occurs. When a speaker cone reaches its physical excursion limit, distortion will spike even higher. When it comes to speakers, there is no good distortion, so operating them within their physical limits is critical to producing accurate sound.

Why is excursion important? When combined with the ability to handle more power, a “better” speaker will play louder when provided with more power. The same features also help to reduce a phenomenon called power compression. Power compression is a reduction in the efficiency of a speaker as its components heat up. The key drawback to power compression is that when the music gets quieter, you turn the volume up, thereby sending more power to the speaker and accelerating the heating effect. In no time, the speaker will fail.

Excursion Linearity

It’s one thing for a speaker to have good power handling and excursion characteristics. It is equally important that the speaker remains linear throughout its excursion-based operating range. All speakers change in their characteristics as excursion increases – a great speaker minimizes these.

Let’s look at a common problem with “simple speakers.” One of the characteristics that limit the high-frequency response of a woofer or midrange driver is inductance. The voice coil of the speaker has some natural inductance because, well – it is a coil of wire. This inductance is increased when we place the voice coil around the T-yoke of a speaker.

This is where the problem occurs: As the coil moves forward, some of it may leave the T-yoke, which will reduce inductance. As the coil moves rearward, inductance may increase. The result is that the speaker has different frequency responses depending on where it is within its range of excursion. Truly excellent speakers use technologies to minimize these effects. The result are speakers that sound just as good at low to moderate drive levels as they do when being pushed hard.

More Frequency Response

This is a bit harder to describe, because sometimes the improvement from a basic to a mid-priced speaker, or a mid-priced speaker to a high-end one, is extended frequency response. More often, it’s smoother frequency response. Better-quality speakers are, ideally, designed to reduce distortion caused by cone resonances, suspension nonlinearities and magnetic field imbalances. As you spend more on speakers, you will see that peaks in their frequency response, especially in the midbass region, are tamed.

Many great speakers still exhibit some cone resonances at high frequencies. As long as the speaker you are using in the adjacent band will play low enough, those peaks are not critical.

Reduced Distortion

When a speaker designer combines an appropriately damped and rigid cone with a carefully designed motor and suspension, the result is a speaker that produces less distortion. Some distortions are very subtle, while others are quite pronounced. Speakers exhibit both even- and odd-ordered harmonic distortions, depending on what component or design issue is to blame.

If you have read our article on distortion, then you know that it is the effect of adding content that was not in the original program material. Harmonic distortion results in even or odd multiples of a specific frequency.

When you hear an amazing speaker, the difference between it and an average speaker is clarity. Smooth frequency response and a lack of distortion make each sound the speaker produces more faithful to the recording. Voices will sound more realistic. Instruments will sound more natural. Complex passages will become easier to understand.

It is also critical to point out that distortions cannot be removed from a signal or sound once created. No amount of equalization can extract those harmonics. Yes, you can reduce their level, but you also reduce the level of original signal information at those same frequencies. The only solution is to use a speaker that does not introduce distortion.

The Right Tool for the Job

Another item that differentiates a good speaker from a great one is its design in terms of application. Let’s use a typical 6.5” midrange/midbass speaker as an example. If the speaker is designed to work in a typical door or rear deck-style installation, the Thiele-Small parameters for that transducer will be optimized for that application. If you attempt to put that speaker into a small kick panel pod that has only 0.1 cubic feet of air space, you will choke it. The low-frequency response will be dramatically reduced; typically, a bump in the midbass region will occur, and it will likely not sound very good. Most 6.5” speakers need an enclosure volume of about 0.6 cubic feet, and some want closer to 1.0 for smooth frequency response.

How do you look for a speaker designed for the right application? That is product knowledge that a properly trained mobile electronics retailer can provide. Do you need a midrange that will work in a small A-pillar pod? Do you need a woofer that will work in an infinite baffle application? Will your midbass driver be used with a subwoofer, or do you need one that will be the sole source of bass in the system? Knowing the intended application for a speaker ensures that the system designer will use it appropriately.

Are More Expensive Speakers Always Better?

Does price always determine performance? In the upper echelon of any audio industry, the rewards for spending exponentially more money diminish. That is to say, the improvement you get from spending $500 on a set of speakers as compared to $200 may not be as dramatic as the difference between $2,500 and $2,200.

Every speaker manufacturer wants you to buy their speakers. They all work hard to come up with great marketing programs to make you want to buy their products. Your goal in choosing an amazing speaker is to ignore the story and listen.

The best way is first to establish a reference. Listen to the best speakers you can find. Don’t worry about the price. You simply want to understand what is available. Then, choose your price point and listen to something in that range. If you can accept the differences, then proceed. If you can’t, re-evaluate your needs or your budget. You can’t get that extra level of clarity, dynamics and detail any other way.

This article is written and produced by the team at www.BestCarAudio.com. Reproduction or use of any kind is prohibited without the express written permission of 1sixty8 media.

According to a AAA survey, the average American drives for about 45 minutes each day. If you compare this time to an eight hour work day, that’s 10% of your work day, on top of the hours you are at your desk. This time is not an insignificant number. If your job involves being on the road, then your time spent behind the wheel can represent half of your day. Being able to be productive while in your vehicle is not only convenient, but in some cases, mandatory to get all the work you need to get done in one day completed. Modern smartphone integration comes to the rescue with Apple CarPlay.

Apple CarPlay History

Apple recognized the need to give people the ability to use their phones in a safe fashion while driving back in 2010. The feature was called iPod Out. BMW announced that it would include iPod Out at the WWDC that year. The concept was that BMW would provide a way for its vehicles to ‘host’ specific applications. The information would be displayed on the factory screen while providing button press and knob rotation information back to the radio.

The next evolution was the introduction of Siri Eyes Free in some Honda Accord and the Acura RDX and ILX models in 2013. Siri Eyes Free is a way to make use of the Siri voice recognition function that Apple Introduced with iOS 5 and the iPhone 4S in October 2011. Apple has marketed Siri as a personal assistant. It allows you to talk to your Apple device to make phone calls, send text messages, set reminders and choose the music you want to hear. Using Siri Eyes Free is simple- press and hold a button on your car radio, wait for the tone, and then speak.

Siri will listen to what you said, convert that to a command and execute it, all without you needing to take your eyes off the road.

Between the time that Apple announced iPod Out and the Geneva Motor Show in March of 2014, Apple was working on the next generation of automotive integration under the code name Stark. At the Geneva Motor Show, they announced ‘iOS in the Car.’ Later that year, Ferrari introduced the new FF model with a fully working version of Apple CarPlay. A few months later, Hyundai announced the Sonata would also feature CarPlay. Most automobile manufacturers have CarPlay available on their mid to high trim level vehicles now.

Apple CarPlay Interface Overview

Apple’s current marketing touts CarPlay as ‘The Ultimate Copilot.’ The features are designed to allow you to communicate with family, friends, and coworkers without significant distraction. The basic feature set of CarPlay includes making and receiving phone calls, choosing the music you want to listen to, getting navigation instructions and sending and receiving text messages.

Apple has worked hard to ensure that the above functions are usable without unnecessary distraction. As soon as you plug your phone into the USB port of your radio, CarPlay launches automatically.

CarPlay does not display incoming text messages on the screen of the radio. Messages are read aloud to prevent users from looking at the dash. However, there are no options presented when asking Apple Maps to plan a navigation route.

Selecting music to play is as easy as requesting the track title, artist or even genre of music you want to enjoy. CarPlay will start playing what you want right away. Apple has also included support for Apple Music- a streaming service powered by iTunes. CarPlay also supports Apple Podcast and Audiobooks. You can select the episode you want to listen to via the touchscreen interface, then play, pause or skip 15 seconds forward or back. Apple CarPlay provides support for several third-party applications including Pandora, Spotify, iHeartRadio, Audible and MLB At Bat.

Apple has released information to application developers in order to allow for the creation of more third party applications. You will see more and more third-party applications added to the CarPlay interface as time passes. Apple will, of course, be selective in their approval process, so don’t expect to see competing navigation applications any time soon.

The Future of Apple CarPlay

Unveiled by BMW in October of 2016, future iterations of CarPlay will function wirelessly. The 2017 BMW 5-Series sedans, when used with an iPhone 6 or newer, will allow users to use CarPlay without the need to plug in the Lightning connector. Wireless CarPlay communicates over a Bluetooth data connection.

Apple is tight-lipped about future functionality of CarPlay. There have been rumours about vehicle function control like remote door lock control, remote starting and trunk release, but so far nothing is set in stone. Another rumored feature is the ability of your phone to remember where you parked your car once you have arrived at your destination.

Apple has led the industry with safe and convenient integration of your smartphone to your vehicle. The future of ‘connected cars’ promises to allow us to share information and offer better communication while remaining safe. If you are interested in adding CarPlay to your vehicle, visit your local mobile electronics specialist retailer. They can show you what options are available for your vehicle.

This article is written and produced by the team at www.BestCarAudio.com. Reproduction or use of any kind is prohibited without the express written permission of 1sixty8 media.

Listening to music goes back to the dawn of man. From banging a few tree branches together to the latest computer-generated pop hit, music is a universal language that everyone can enjoy. People who put significant effort into the accurate reproduction of the music they enjoy are often called audiophiles. There is a running joke that audiophiles sometimes concentrate more on listening to the equipment they use to make great sound than to the music itself. While this so-called joke is certainly true during the purchasing and setup stage, once audiophiles have their systems sounding the way they want, the focus turns to enjoying the music.

If you get into a discussion about choosing high-end audio equipment, inevitably someone will suggest that you seek out a reference. The ultimate reference is a live performance. We want to be clear: Artists don’t make money like they used to from album sales. Supporting the performers you enjoy by attending concerts not only is great entertainment for you, but allows the performer to make a few dollars.

With this in mind, the reference for what the reproduction of a recording should sound like is not a live performance.

This article provides a generalization about most music heard on a car radio. There are exceptions; we understand that. We want you to think outside what you were once told.

How Music is Recorded

For most music, each musician or performer is in a recording studio. Microphones are used to capture the subsequent performance. For a singer, the mic is usually directly in front of them. For a group of singers, each individual may have a mic, or they may be gathered around a single centralized mic or a pair of microphones set up to capture the performance in stereo. For someone playing an electric guitar, the mic is most likely in front of the amplifier.

In some recording sessions, the amplifier is placed in a small room and cranked to 11 so it clips and distorts the sound, and that gets recorded. This overdriven performance gives the guitar “a certain sound” that some producers and engineers like.

These techniques go on and on. At the very extreme might be a drum kit. Some recording engineers have microphones on each drum and cymbal, then overhead mics to pick up rim shots and another set of mics forward of the drums to capture the room’s acoustics. Consider this as well: The sensitivity pattern of a microphone is not so narrow that it only captures what is directly in front of it, so each microphone captures information from all of the drums and cymbals, to some extent.

The specific placement of a microphone relative to the instrument it is recording has a dramatic effect on what it captures. Let’s take a look at recording an acoustic guitar. A microphone a few inches in front of the soundhole will capture significantly different information than if the mic is located halfway up the fingerboard. The question now becomes, What microphone position is correct? The next question is, If we were standing in the recording studio with the guitarist, would we hear the same thing that the microphone recorded?

The Effect of the Studio

Each make and model of instrument has its own unique characteristic set of harmonics that gives it a “sound.” So, too, does each studio. Some are very large with acoustically absorbent surfaces. Some are very small and have a “live” sound. Placing the same performer with the same instrument in each of these studios will result in a different sound in the listening and recording position. If you haven’t seen it, watch the Foo Fighters’ documentary, “Sonic Highways.” It provides a great look at how different studios can affect the sound of a performance.

Let’s review what we have so far. For a given performance, we have a unique performer, their choice of instrument, the environment, the choice of microphone and the microphone placement that affect what we hear. We are just warming up!

The Control Room

In a studio, the musicians perform in what is called the live room or sometimes an isolation booth. We already know that the shape, size and finish of these rooms affect what gets recorded, but what about the control room? This is a separate room from where the performance is taking place and where the recording engineer and producer typically sit. In this room are the control console, computers to capture and process the recording, and – most importantly – monitor speakers.

In a gross and undetailed generalization, once each microphone channel has been recorded, the producer manipulates each channel to produce the final mix. This manipulation can be as simple as the left-to-right panning and level of each instrument, or as complex as equalization, compression, gating, adding distortion and much more. Often, many processes are applied simultaneously to each channel. It can take weeks or months to mix a single complex track.

We all know how different each and every set of speakers can sound. When we add the acoustics of the control room to the mix (pun intended), the number of variables increases dramatically. Listening to the same master track in two different control rooms can result in dramatically different results. This begs the question once again of what is correct, and how do we know?

Measuring and calibrating the frequency response of the monitoring speaker system will certainly help a lot, but that doesn’t account for the distortion characteristics of the speakers. Let’s say the speakers sound a little warm because the midbass driver has a resonance problem due to nonlinearities in the spider. Even a mild resonance can wreak havoc with the perceived balance of the speaker. Worse, you can’t EQ it back out. Yes, you can flatten the overall response level of the system, but if you are getting some 120 Hz content because the cone is playing 60 Hz, that can’t be removed. Lack of distortion in speakers is crucial to accurate reproduction.

Circle of Destruction?

So, we have our performers in a studio playing music. Microphones are set up in specific locations to capture that performance and the acoustics of the environment. The recording engineer is listening to what is captured by the microphones on that studio’s monitor system. The engineer makes adjustments to the mix based on what he hears. The music is then sold to the public. We listen to it on our reference systems and, if everything has gone according to plan, we enjoy it.

But what if we don’t enjoy it? What if we think what we hear doesn’t have enough bass or has too much high-frequency information? Do we make adjustments to the tone controls on our radios? Does the act of attempting to reproduce sound evolve from a scientific task to a form of art?

What about the Live Performance?

Our friends and experts suggested that our reference for listening to music be a live performance. Is it an acoustic performance? Is it in an open-air stadium or a small club? Are any band members drunk? The number of variables that can affect what we hear is nearly infinite. Your best hope of using a live performance as a reference is to listen to a recording of that particular performance. If the recording took place anywhere else, it just might not work. Will the experience be worthwhile and enjoyable? The answer to that is a resounding yes! That performance is not our reference.

What is our Reference For Great Sound?

For a given performance in a given location with a specific set of instruments and microphone placement techniques, the absolute reference for what that performance should sound like would be the control room where the final mixing took place. Even if we expanded our example to a simple two-microphone recording of a choir in a massive cathedral, the recording engineer is likely to make some small adjustments, using a reference audio system or reference headphones, before that recording is released to the public.

Reproducing and listening to music is about more than just frequency response. Time response, reflections in the listening environment and much more affect what we hear. The best way to develop a reference is to listen to the same recording on as many great systems as you can. Ignore the make, model, color and cost of the equipment you are auditioning. Work to quantify the difference between what you hear and what you have heard previously.

After a while, you will start to develop a reference for what sounds good. Continue to listen. Evaluate new products, new applications and new environments. Sure, a personal preference is still involved, but that is your contribution to the art of recording and enjoying music: You can make it sound the way you want.

Your local specialist mobile electronics retailer will have many different systems you can audition. Drop by and ask to listen to a few. If they have a demo car, then definitely listen to that! Listening to music is a lot of fun – never forget that.

This article is written and produced by the team at www.BestCarAudio.com. Reproduction or use of any kind is prohibited without the express written permission of 1sixty8 media.